Just replace the script.dat (installed with the tr5 pc demo) with this one.
Run the game, and you will be prompted to select a level, just select the 'The Colosseum' level.
In the level, press and hold the keys 'd' 'o' 'z' 'y'. (Like in the level editor)

When flying:
	Alt - 'Fly' forward
	Ctrl - Brighten the area up
	Direction keys - Fly left/right/up/down
	Shift - Return to normal mode again.

I hope you enjoy this patch - (Bart).